Excisional stereotactic apparatus

ABSTRACT

An excisional biopsy needle assembly for use in combination with a stereotactic platform for excising tissue from the interior of the body. The biopsy needle includes a rotatable flexible blade that is capable of transforming between a contracted configuration for piercing into the interior of the body and an expanded configuration in which the flexible blade is expanded relative to the shaft of the needle for excising tissue. The needle assembly may be mounted in a stereotactic needle for a breast biopsy procedure that digitally directs the needle tip into a lesion with the flexible blades in a contracted configuration, then expands the flexible blades to the expanded configuration and rotates the blades thus excising tissue in a region having a cross sectional dimension that is large in relation to the cross section of the needle shaft. The excised tissue is extracted from the needle tip through an aspiration channel.

This application is a continuation of application Ser. No. 08/292,479filed Aug. 18, 1994, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to surgical instrumentation and more particularlyto an instrument for use with an image-directed apparatus to perform anexcisional biopsy, for example, of a lesion in a patient's breast. Theinvention and associated method relate to a manner in which biopsytissue may be excised and extracted through a minimally invasiveincision.

2. Description of Prior Art

It often is necessary to biopsy tissue from the interior of the body fordiagnostic purposes. For example, when a physician discovers asuspicious breast lesion, a biopsy typically is performed on a smalltissue sample to determine whether to remove the lesion or to performanother more invasive surgery. It remains common practice to use an opensurgical approach to recover a tissue sample for biopsy purposes. Suchan open excisional biopsy causes trauma and may leave undesirablescarring.

In many cases, a needle biopsy approach is employed. A "fine needleaspiration" approach utilizes a hollow 22 gauge needle wherein a smallamount of tissue may be aspirated into the needle bore which then may bebiopsied. Alternatively, a small core of tissue may be sampled with a"true-cut" or "quick-cut" needle in which an 18 gauge hollow needle witha sharpened tip reciprocates over a notched stylet. The elongate notchin the stylet collects a tissue core for biopsy purposes. Suchneedle-biopsy approaches cause little trauma but suffer from thedisadvantage of recovering only a small amount tissue for biopsypurposes.

A recently developed approach is called a "large-core" stereotacticneedle biopsy in which a 14 gauge hollow needle is employed togetherwith an image-directed technology for digitally localizing the biopsyneedle in relation to a breast lesion. To utilize the stereotacticneedle apparatus, the patient lays prone on an operating platform thatexposes and holds the breast in a stationary position below theplatform. An x-ray stereo imaging unit is mounted below the platform anddisplays a stereo image of the lesion on a video monitor. A "large-core"needle assembly is mounted on a traveling arm below the platform and maybe positioned in three axes by digital coordination with the stereox-ray images. The large-core needle employs a 14 gauge hollow needlethat reciprocates over a notched stylet similar to above-described"true-cut" needle. After the needle tip is digitally positioned justoutside the breast, a double spring-loaded needle first projects thestylet through the lesion and then instantly projects the needle overthe notched stylet to excise tissue within the notch in the stylet. Theprincipal advantage of the stereotactic needle biopsy over other needlebiopsy approaches is that the image-directed apparatus insures thattissue is excised from the exact site of the lesion. The 14 gauge needlealso recovers a larger tissue sample than other needle biopsyapproaches. Also, such a stereotactic needle biopsy causes little traumabecause of the small diameter of the needle.

The stereotactic needle approach still does not recover a large tissuesample. Even in repeated cycles of insertion and withdrawal, 5 to 6cycles being typical, the 14 gauge stereotactic needle can excise andextract only a small portion of a suspect lesion. In contrast, in anopen excisional biopsy, the entire lesion may be removed. There istherefore a need for new instruments and methods for excising andextracting biopsy tissue from the interior of the body through aminimally invasive incision, and particularly for performing anexcisional biopsy on a breast lesion through a needle incision utilizinga stereo image-directed apparatus to digitally localize the excision.

SUMMARY OF THE INVENTION

In general, the instrument and method in accordance with the presentinvention are utilized to excise and extract tissue from the interior ofthe body through a minimally invasive needle incision. The instrument isadapted for use with a stereotactic needle apparatus to precisely directthe tip of the needle assembly to the site of the lesion.

The instrument incorporates a disposable flex-blade needle cutterincluding:

(a) a hollow sleeve with a needle tip incorporating flexible rotatableblades that are movable between a first position in which the blades arecontracted relative to the needle shaft for piercing into a patient'sbody and a second position in which the flexors are expanded in an arcoutward relative to the needle shaft for excising tissue,

(b) a blade-flexing mechanism for flexing the blades between the firstand second positions;

(c) a rotation mechanism for rotating the flexors;

(d) an infusion channel within the hollow sleeve for supplying salinesolution to the region of the flexors;

(e) an aspiration channel associated with the flexors for extractingfluids and excised tissue; and

(f) a needle insertion mechanism for piercing the needle tip intotissue.

In using the flex-blade needle to remove a breast lesion, the surgeonlocks the needle in an actuator incorporating actuation mechanisms,including a blade flexing mechanism, a blade rotation mechanism, aneedle insertion mechanism, a saline infusion source and an aspirationsource. The patient is positioned on a stereotactic needle apparatus.The actuator body then is fitted to the traveling arm of thestereotactic needle apparatus. The physician employs conventionaldigital imaging technology to direct the tip of the needle to thecorrect "x", "y" and "z" coordinates just exterior to the skin of thebreast. The surgeon then selects a pre-programmed actuation cycle on acontroller for the particular diameter of the needle and the dimensionsof the tissue to be excised and extracted. The controller in sequenceadvances the needle tip with the flexors in the contracted position intothe breast to the site of the lesion and then rotates and simultaneouslyflexes the flexors to the expanded position from the contractedposition, thus incising tissue. At the same time, saline solution isinfused into the region of the rotating flexors through the infusionchannel while an aspiration source aspirates the excised tissue mixedwith the saline through the separate aspiration channel. The extractedtissue is collected in a filter in a tissue-sampler. The controller thenautomatically returns the flexors to the contracted position andwithdraws the needle from the breast.

In general, the present invention provides an instrument and method forexcising and extracting tissue from the interior of the body (not justthe breast) through a small diameter needle. The transverse sectionaldimension of the excised tissue is advantageously large in relation tosectional dimension of needle shaft through which the tissue isextracted.

The present invention provides an instrument and method that cooperateswith a stereotactic needle apparatus to digitally localize theexcisional biopsy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of the present invention with theflex-blades of the needle in a flexed position.

FIG. 2 is an enlarged axionometric view of the distal end of theflex-blade needle of the instrument of FIG. 1.

FIG. 3 is an enlarged axionometric view of the flex-blade needle of theinstrument of FIG. 1 taken along line 3--3 of FIG. 1.

FIG. 4 is a transverse sectional view of the flex-blade needle of FIG. 3taken along line 4--4 of FIG. 3.

FIG. 5 is an elevational view of a cutter assembly with flex-blades in afirst position for axial penetration of tissue.

FIG. 6 is a longitudinal sectional view of the cutter assembly of FIG. 5taken along line 6--6 of FIG. 5 rotated 90°.

FIG. 7 is a sectional view of a component of the cutter assembly of FIG.5.

FIG. 8 is a longitudinal sectional view of the cutter assembly similarto FIG. 6 with the flex-blades in second position for excising tissue.

FIG. 9 is a partial sectional view of the actuator of FIG. 1 taken alongline 9--9 of FIG. 1 rotated 90°.

FIG. 10 is a partial sectional view of actuator of FIG. 9 in analternative position.

FIG. 11 is an axionometric view of an alternative embodiment of aflex-blade needle.

FIG. 12 is an axionometric view of an alternative embodiment of aflex-blade needle.

FIG. 13 is an axionometric view of an alternative embodiment of aflex-blade needle.

FIG. 14 is an elevational view of an alternative embodiment of aflex-blade cutter.

FIG. 15 is an elevational view of an alternative embodiment of a cutterassembly in a first position.

FIG. 16 is a longitudinal sectional view of the cutter assembly of FIG.15 taken along line 16--16 of FIG. 15 rotated 90°.

FIG. 17 is an elevational view of a component of the cutter assembly ofFIG. 15.

FIG. 18 is a longitudinal sectional view of the cutter assembly similarto FIG. 16 in a second position.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

By way of example, FIG. 1 illustrates a excisional needle biopsy deviceor instrument 5 in accordance with the present invention. Instrument 5is adapted for use with a conventional stereotactic needle apparatus,for example, a Model DSM unit (Digital Spot Mammography) made by Lorad,Inc. of Danbury, Mass.

Instrument 5 includes a disposable flex-blade cutter subassembly 10 (seeFIG. 1). FIGS. 2-3 are axionometric views of the distal tip offlex-blade cutter 10 in alternative positions. In FIG. 2. flex-bladecutter 10 is illustrated with flexible blades or flexors 15 in acontracted or first position as when cutter 10 is configured for axialpiercing into a patient's body. In FIG. 3, cutter 10 is depicted withflexors 15 in an expanded or second position as when the cutter isrotating at high speed to excise and extract tissue from atoroidal-shaped region.

Flexors 15 are fabricated from any suitable material such as stainlesssteel ribbon having a thickness ranging e.g. from 0.002" to 0.015" andwidth ranging e.g. from 0.020" to 0.120" depending on the desiredflexing characteristics and the dimensions of tissue to be excised(these dimensions are not limiting). For example, flexors 15 may be madeof proprietary type UHB Stainless AEB-L by Uddeholm Corporation ofPortland, Oreg. Each flexor is sharpened on one blade edge 17 or may besharpened on both edges.

Still referring to FIGS. 2-3, the ends of flexors 15 are attached toproximal and distal hinge members respectively 20 and 22, that are madeof any suitable resilient plastic material, for example Nylon or Delrin.The hinge members 20, 22 are injection-molded and grip the proximal anddistal flexors ends respectively 23 and 24, through perforations 25 inthe flexors. Resilient proximal and distal hinge portions respectively26 and 28, have a thin cross-sections to attain suitable flexibility.

Outer sleeve 30 with proximal and distal ends respectively 31 (see FIG.5) and 32, is fabricated from a thin-walled hollow tubular member,preferably stainless steel. Outer sleeve 30 is approximately 150 mm. inlength (not limiting) and may be manufactured is various externaldiameters, for example 1 mm. to 5 mm. (not limiting). Bore 33 in outersleeve 30 is dimensioned to accommodate the rotation of rotator sleeve40.

Rotator sleeve 40 has swaged flat regions 44 on two diametricallyopposed sides, best illustrated in FIGS. 3-4. Sharp needle tip 45 isfixed to the distal end of rotator sleeve 40. Flat-sided bore 46 inproximal hinge member 20 is dimensioned to slide axially over swagedflats 44 but resist rotation around the swaged flats. Longitudinalgrooves 47 provide a fluid channel between proximal hinge 20 and sleeve40. Similar bore 48 in distal hinge member 22 is dimensioned to pressfit over swaged flats 44 thereby resisting rotation around rotatorsleeve 40. Annular groove 49 in the reduced diameter proximal shank ofproximal hinge member 20 cooperates with indentation 50 in outer sleeve30 in a slip-type fit to allow hinge member 20 to rotate relative toouter sleeve 30. Apertures 55 in rotator sleeve 40 in the region offlexors 15 communicate with interior bore or aspiration lumen 56 insleeve 40. In the transverse sectional view of FIG. 4, it can be seenthat a space exists between the outer surface of swaged flats 44 andbore 33 of outer sleeve 30 to provide infusion channel 58.

FIGS. 5-8 depict various views of cutter 10 with a component partdisassembled to explain the manner in which flexors 15 are flexedbetween the first (contracted) position of FIG. 2 and second (expanded)position shown in FIG. 3.

Referring to FIGS. 5-6, cutter 10 has a body that includes a mainhousing 60 and a spring housing 62 that are generally cylindrical inshape and are made e.g. of injection-molded plastic. Spring housing 62is fixed with adhesives or other suitable means into a receiving bore 63in main housing 60.

Referring to FIG. 6, actuator sleeve 65 for actuating flexors 15 isdimensioned to reciprocate in bore 66 that extends through main andspring housings, 60 and 62. The proximal end of outer sleeve 30 is fixedin the distal end of actuator sleeve 65. Compression spring 68 iscaptured in spring bore 69 and engages flange 70 of actuator sleeve 65to urge the sleeve to its proximalmost position which in turn causesouter sleeve 30 in cooperation with proximal hinge 20 to maintain theflexors in the first (contracted) position (see FIG. 2). In FIG. 8,actuator sleeve 65 is shown in an alternative position partiallyprojected outward (distally) with spring 68 being partially compressedwhich in turn causes the distal sliding of outer sleeve 30 to flex theflexors. Referring to FIGS. 5-6 and 8, it can be seen that proximal end72 of actuator sleeve 65 extends proximally from main housing 60 adistance referred to as extension distance "E" and a distal forceapplied to proximal end 72 will cause flexors 15 to flex.

A mechanism is provided to allow actuator sleeve 65 to slide axially butprevent the sleeve from rotating. As shown in FIG. 6, longitudinalgroove 75 in actuator sleeve 65 extends into bore 76 in the sleeve. Slot75 is aligned with latch 77 and the inwardly projecting arm 78 of thelatch extend through slot 75 inward toward the axis of actuator sleeve65. Latch 77 has resilient pivot arms 79 (see FIG. 1) that snap fit intomain housing 60 and yieldably maintain latch 77 in the latched positionshown in FIGS. 5-6 and 8. Projecting arm 78 extends through afluid-tight flexible seal 80 in main housing 60 into slot 75.

Referring to FIG. 7, rotator sleeve 40 and more particularly itsproximal end is fixed to e.g. plastic rotator stem 85. Stem 85 withdistal tapered region 86 is dimensioned to freely rotate in bore 76 ofactuation sleeve 65. Bore or aspiration lumen 56 in sleeve 40 is alignedwith counter bore 87 in stem 85. Diametrically opposed apertures 88 instem 85 communicate with counterbore 87. Rotator sleeve 40 and stem 85are maintained in a fixed axial position relative to cutter 10 asrotator stem 85 rotates yet still allowing actuator sleeve 65 toreciprocate over the stem. Annular groove 89 in stem 85 is engaged bythe tip of projecting arm 78 of latch 77, which allows the stem 85 torotate but not move axially.

The proximal end of rotator stem 85 includes a female spline-receivingfitting 92 (see FIGS. 5 and 7). The spline fitting 92 is adapted toengage a cooperating fitting in a motor further described below.Compression spring 93 in the proximal end of stem 85 urges the stem andcutter 10 from engagement with the motor and actuator 100 furtherdescribed below.

Fluids may be infused under pressure, for example saline solution, tothe region of flexors 15, by a conventional operating room (OR) salinesource connected to Luer-type fitting 102 in cutter 10 (see FIG. 1).Referring to FIG. 8, fluid passageway 103 in fitting 102 communicateswith the internal spring bore 69 in spring housing 62. Fluid in springbore 69 may flow freely through inflow apertures 105 into bore 76 inactuator sleeve 65. Once fluid is under pressure within the actuatorsleeve bore 76, it may flow distally over taper 86 in stem 85 and intoinfusion channels 58 within bore 33 to the region of proximal hingemember 20 and thereafter though longitudinal grooves 47 in flat-sidedbore 46 of hinge 20 to escape to the region of the flexors. Once fluidis under pressure within actuator sleeve bore 76, it is prevented fromflowing in the proximal direction by "O"-ring 90 mounted around rotatorstem 85 in actuator sleeve bore 76, as shown in phantom view in FIG. 8.Fluid in spring bore 69 is prevented from flowing around the outersurface of actuator sleeve 65 by distal "O"-ring 109 and medial "O"-ring111. Thus, fluid infusion to the flexors may occur when actuator sleeve65 is in either a retracted or projected position.

Fluids may be aspirated from the region of flexors 15 by a conventionalOR suction or aspiration source connected to Luer-type fitting 112 inmain housing 60. Referring to FIG. 6, fluid passageway 113 communicateswith the bore 66 in main housing 60. Suction pressure in bore 66 flowsthrough longitudinal slot 115 into bore 76 in actuator sleeve 65. Oncesuction pressure is within the actuator sleeve bore, the suctioncommunicates with apertures 88 in rotator stem 85 as the stem rotates.Apertures 88 allow suction pressure to flow through counterbore 87 intoaligned bore or aspiration lumen 56 in rotator sleeve 40. Such suctionpressure then aspirates fluids from the region of the flexors thoughapertures 55 in the rotator sleeve (see FIG. 3). Suction pressure withinbore 66 is prevented from escaping around the outer surface of actuatorsleeve 65 by medial "O"-ring 111 and proximal "O"-ring 110. Also,suction pressure does not escape around latch projecting arm 78 becauseof fluid-tight seal 80. Thus, aspiration pressure to the region offlexors 15 is provided when actuator sleeve 65 is any position, eitherretracted or projected (see FIGS. 6 and 8).

Actuator 100 (see FIGS. 9-10) provides various mechanisms formechanizing cutter 10, and more specifically reciprocates actuatorsleeve 65 to flex the flexors, rotates the flexors and means for axiallymoves cutter 10 to pierce through tissue into the interior of the body.Actuator 100 includes four housing components ("A", "B", "C" and "D")that are axially aligned and made of metal or plastic.

Actuator 100 includes a latch for releasably locking cutter 10 into theactuator. As seen in FIG. 9, housing "A" at the distal end of actuator100 has a female conical-shaped bore 120 that receives theconical-shaped proximal end 122 of main housing 60 of cutter 10. Housing"A" is fixed in counterbore 123 in housing "B". Locking collar 124 iscaptured between housings "A" and "B" and rotates around cylindricalportion 125 of housing "A". The latch includes a round bearing 128projecting partially though partial radial bore 129 to engage annulargroove 132 in main housing 60. Locking collar 124 is configured with avariable depth groove 135 in its inner bore 137 that pushes bearing 128radially inward to a locking position as shown in FIG. 9. Torsion spring139 urges locking collar to rotate to the locking position. By rotatinglocking collar 124 and overcoming the force of torsion spring 139, theradial depth of groove 135 increases, thus permitting bearing 128 to bedisplaced outwardly to release its engagement with annular groove 132and permitting cutter 10 to be withdrawn distally.

Male hex-configured region 140 of main housing 60 fits into femalehex-receiving form 141 in actuator 100 (see FIG. 10) to prevent rotationof the cutter 10 relative to actuator 100.

A mechanism is provided for rotating rotator sleeve 40 and rotator stem85 thus rotating flexors 15. Referring to FIGS. 9-10, the rotationmechanism is motor 142 such as commercially available from Micro Motorsof Santa Ana, Calif., for example, model number MMR-0700 or MMR-0014.The distal end of motor 142 has male threads 143 that are fitted intohousing "C". Housings "B", "C" and "D" are fixed together by screws 144(see FIG. 1) or other suitable fasteners. Motor 142 is a turbine that isrotated by pressurized air supply line 146 and cooperating air exhaustline 147 that are fixed to a quick disconnect coupling 149, for example,similar to part K-212010 from Small Parts, Inc., of Miami Lakes, Fla.The instrument alternatively may be powered by an electric motor. Thepressurized air supply is fed through controller 150 (FIG.1) which mayinclude an electronic feedback circuit (not shown) capable of sensingthe load on rotating flexors 15 and rotator sleeve 40 as tissue isexcised to maintain optimum torque and rotational speed within definedparameters.

A four-sided spline 152 at the distal end of motor shaft 153 engagesfemale spline-receiving fitting 92 in the proximal end of rotator stem85 (see FIGS. 5 and 7).

An actuator is provided for flexing the flexors 15 to the second(expanded) position as shown in FIG. 3 from the first (contracted)position as shown in FIG. 2. The actuator includes reciprocating plunger160 that pushes on proximal end 72 of actuator sleeve 65 as plunger 160moves to and fro in cylindrical plunger chamber 162. Compression spring165 engages flange 166 and yieldably maintains plunger 160 in itsproximalmost position shown in FIG. 9 with extension distance "E" againindicating a range of axial travel. In FIG. 10, plunger 160 isillustrated in its distalmost projected position. To move plunger 160 toits second position from its first position, pin 167 which is fixed inflange 166 may be pushed distally by a piston 168 within aquick-disconnect hydraulic fitting 169 (see FIG. 1).

A needle insertion mechanism is provided for piercing and withdrawingthe distal end of cutter 10 with respect to a patient's body. Referringto FIGS. 9-10, actuator 100 has feet 170 that slidably engagelongitudinal tracks 172 in guide 175. Guide 175 shown in FIG. 10 allowsfor travel of approximately 2 to 4 inches (not limiting). Actuator 100is yieldably maintained in its proximalmost sliding position withintracks 172 by extension spring 176 shown in phantom view in FIG. 10.Guide 175 has fitting 177 that cooperates with quick-disconnecthydraulic piston fitting 180 (see FIG. 1). Referring to FIG. 1, piston182 is illustrated in a withdrawn position with a phantom view of itsprojected position. To move actuator 100 to its projected position fromits withdrawn position, controller 150 uses a hydraulic line to actuatepiston 182 thus making actuator 100 slide distally in tracks 172. Guide175 is adapted for locking in the traveling arm of the stereotacticneedle assembly by thumbscrews or other suitable means.

A controller sequences the actuation of the projecting mechanism, therotation mechanism and the blade-flexing mechanism as well as the salineinfusion and aspiration. Controller 150 incorporates integratedcircuitry to automatically actuate the various actuation mechanisms inpre-programmed cycles. The cycles differ for each different diameter ofcutter 10.

A mechanism is are also provided for collecting extracted tissue.Referring to FIG. 1, the aspiration source is provided with a tissuefilter subassembly 210 shown schematically. A conventional autoclavablestainless steel filter with replaceable filter membranes may be providedto separate tissue from infused saline solution, and may be part no.Q-202025 from Small Parts, Inc., of Miami Lakes, Fla.

Operation and use of instrument 5 for excising tissue from a lesion in abreast is briefly described as follows. The surgeon mounts actuator 100on the traveling arm of a conventional stereotactic needle apparatus.The actuation lines are connected between actuator 100 and controller150.

A patient is prepared with suitable local anesthesia and positioned onthe platform of the stereotactic needle apparatus. The surgeon then fitsa disposable cutter 10 into actuator 100. The locking collar 124 isrotated overcoming the force exerted by torsion spring 139 thuspermitting bearing 138 to be displaced radially outward. The proximalend of cutter 10 is introduced into conical bore 120 and the release ofcollar 124 causes bearing 138 to project radially inward into annulargroove 132 to lock cutter 10 in place. The cooperating hex-shapes 140and 141 of cutter 10 and actuator 100 angularly lock the cutter relativeto the actuator.

The surgeon then uses the digital controls on the stereotactic needleapparatus to direct tip 45 of cutter 10 to a position aligned with thelesion but still about 5 mm. outside the patient's skin on the "z" axis.The surgeon then nicks the skin with a scalpel. The surgeon then selectsa pre-programmed actuation cycle on controller 150 for the particulardiameter of cutter 10 and the dimensions of the tissue to be excised.Upon pressing a button to actuate a cycle, controller 150 first movesactuator 100 distally to pierce needle tip 45 directly through thebreast lesion as can be seen on the video monitor. Then, the controllersimultaneously and sequentially rotates flexors 15, flexes the flexorsto the second (expanded) position from the first (contracted) positionand infuses flexors 15 with saline fluid which flows through infusionchannel 58 between outer sleeve 30 and rotator sleeve 40. Also at thesame time, the aspiration source aspirates saline fluids mixed withexcised tissue through apertures 55 in rotator sleeve 40 inward offlexors 15 and thereafter through aspiration lumen 56. Aspirated tissueis separated from saline solution fluid within tissue filter subassembly210. The surgeon may view the pre-programmed actuation cycle on thevideo monitor. The actuation cycle concludes with controller 150automatically withdrawing needle tip 45 from the breast.

Referring to FIG. 11, an alternative embodiment of a flex-blade cutteris shown in which cutter 250 has flexors 255 and proximal and distalhinge components 260 and 262 made of a unitary injection-molded plasticmember. Proximal and distal hinge elements 264 and 266 are thin andflexible in cross section to provide suitable flexing characteristics. Aresilient plastic such as Delrin is suitable for a unitary flex-bladecutter and may still have a sufficiently sharp edge for a single use toexcise tissue.

Referring to FIG. 12, an alternative embodiment of a flex-blade cutterfor a small diameter cutter is shown in which cutter 280 has a pluralityof flexors 285 made of flexible wire such as stainless steel. Theproximal and distal regions 286 and 288 of each wire comprises a hinge.The wires are fixed in proximal and distal blade spindles 290 and 292,for example as inserts in an injection molding process, and the assemblycooperates with rotator sleeve 295 as described in the previousembodiment. The wires may range in diameter from 0.005" to 0.050" (notlimiting) depending on the diameter of cutter 280. To enhance theexcising ability of a cutter with such wire flexors 285, the flexors mayhave an abrasive finish, such as a passivated or sandblasted finish, toenhance its ability to excise tissue as it rotates.

Referring still to FIG. 12, flexors 285 may also be fabricated out of avery flexible plastic material such as a plastic monofilament and besuitable for excising tissue. In an embodiment with a very flexibleflexor 285, the blade flexing mechanism to move the flexors to thesecond (expanded) position from the first (contracted) position mayinclude only the centrifugal force on rotator sleeve 295 which willcause the flexors to bend radially outward as depicted in FIG. 12 underhigh speed rotation which will overcome pressure of tissue on theflexors. In any cutter employing such centrifugal force forblade-flexing, the spring 68 (see e.g., FIG. 6) in the cutter housingwill move the flexors to the first (contracted) position from the second(expanded) position after rotation of sleeve 295 is slowed and thenstopped.

Referring to FIG. 13, an alternative embodiment of a rotatableflex-blade cutter is shown in which cutter 310 has a single flexor 315made of a flexible wire is at least partially helically wrapped aroundrotator sleeve 320. The flexor 315 is maintained in either a contractedor expanded position by counter-rotating distal spindle 322 relative toproximal spindle 324. Splines 327 are adapted to engage an outer sleeve(not shown) that in concentrically mounted over inner sleeve 320. In anycutter employing such a helically wrapped flexor 315, the flexor alsomay be flexed by centrifugal force on the rotator sleeve as describedabove. In any cutter with a helically wrapped flexor 315, the force orspring constant within the flexor itself may be utilized to move theflexor 315 to the first (contracted) position from the second (expanded)position after rotation of sleeve 320 is slowed and stopped.

Referring to FIG. 14, an alternative embodiment of a flex-blade cutter350 in which the tissue aspiration mechanism includes an auger member354 which rotates in cooperation with flexors 355 to draw excised tissueinto the bore in sleeve 360.

It should be appreciated that all of the above-described embodiments ofcutters may include a reciprocating external protective sleeve (notshown) to cover the flexors of the cutter in the first (contracted)position to facilitate piercing into tissue. Such an external sleevethen would slide proximally to expose the flexors and thereby permit theflexors to flex to the second (expanded) position.

Actuator 100 also may be employed to actuate a non-rotating embodimentof a needle-cutter 510 that is illustrated in FIGS. 15-18. Thisembodiment is adapted to excise tissue with a reciprocating needlesleeve only.

In FIGS. 15-16, it can be seen that main housing 530 and spring housing532 are similar to the above-described embodiment. The actuator sleeve535 functions as in the previous embodiment and reciprocates throughbore 536 in the spring and main housings, 530 and 532. Actuator 100 iscapable of reciprocating actuator sleeve 535 a distance again referredto as extension distance "E".

Referring to FIG. 15, excising sleeve 540 is fabricated from athin-walled hollow stainless steel tube. The distal end 541 of excisingsleeve 540 is ground and honed circumferentially as a cylindricalcutting edge 542 to excise tissue as the cutting edge 541 is projectedin a distal direction over needle tip 545. The excising sleeve 540 isapproximately 200 mm. in length and may be manufactured in variousexternal diameters, for example 1 mm. to 5 mm. (not limiting). Bore ortissue-collecting lumen 548 in excising sleeve 540 collects excisedtissue cores and is aligned with bore 549 extending through actuatorsleeve 535.

Referring to FIG. 17, obturator 550 includes a shaft portion 552 and apiercing tip 545 fixed to wire 555, for example by laser welding, and isdimensioned to slide in bore 549 in actuator sleeve 535. Shallowlongitudinal grooves 556 in the outer surface of shaft 552 optionally toallow aspirated air to travel from the distal end of lumen 548 toaspiration port 560. Latch arm 567 with projecting tip 568 extendsthrough slot 569 into bore 549 and engages annular notch 562 in shaft552 to maintain obturator 550 in a fixed position relative to mainhousing 530 thus allowing actuator sleeve 535 to freely reciprocate.

The operation of reciprocating needle-cutter 510 employs theabove-described needle insertion mechanism to pierce the needle tip intoa breast lesion with the needle tip 545 held in registration with theexcising sleeve 540 as shown in FIG. 18. The reciprocating mechanismwithin actuator 100 then is used to move the excising sleeve proximally(see FIG. 15) and then distally (see FIG. 18) to excise a large core oftissue. Such a tissue coring cycle may be repeated. The tissue core canbe recovered from bore 549 by releasing latch 567 an pulling obturator550 proximally from main housing 530.

Although the invention has been described in connection with a breastbiopsy procedure, it should be appreciated that the device and method ofthe invention can be used in other minimally invasion tissue excisingprocedures. For example, the device can be used to excise lesions withinmuscles or organs such as the liver. It should also be appreciated thatthe needle assemblies may be fitted to a hand held motor housing with apistol grip to manually excise and extract tissue from the interior of abody region or organ and be within the scope of the invention.

I claim:
 1. An excisional apparatus for use in excising tissue from theinterior of a body, comprising:a platform; and a needle assembly mountedon the platform, the needle assembly including:(a) a longitudinallyextending extension sleeve having proximal and distal ends and defininga longitudinal axis, wherein said distal end carries at least oneexcising member movable between a first position in which the excisingmember is contracted relative to said axis for insertion into theinterior of the body and a second position in which the excising memberis expanded relative to said axis for excising tissue, said proximal endof the sleeve being coupled to a traveling arm of the stereotacticplatform, the excising member having a tip for penetrating tissue; (b)an excising member-expanding structure operatively connected to theexcising member; (c) an excising member-contracting structureoperatively connected to the excising member; and (d) a rotational motoroperatively connected to the excising member.
 2. The apparatus of claim1 wherein the excising member comprises a rotatable flexible blade. 3.The apparatus of claim 2 wherein the blade comprises a flat flexiblemetal strip.
 4. The apparatus of claim 2 wherein the blade comprises aflat flexible plastic strip.
 5. The apparatus of claim 2 wherein theblade comprises a flexible metal wire.
 6. The apparatus of claim 2wherein the blade comprises a substantially round flexible plasticmaterial.
 7. The apparatus of claim 1 wherein the excising member has atleast one sharp knife-like edge.
 8. The apparatus of claim 1 wherein theexcising member has an abrasive surface.
 9. The apparatus of claim 1wherein the excising member in the first position is disposedsubstantially longitudinally with respect to the axis of the extensionsleeve.
 10. The apparatus of claim 1 wherein the excising member in thefirst position is disposed at least partially helically with respect tothe axis of the extension sleeve.
 11. The apparatus of claim 1 whereinthe excising member-expanding structure includes a reciprocating elementincorporated into the extension sleeve.
 12. The apparatus of claim 1wherein the excising member-expanding structure includescounter-rotating elements incorporated into the extension sleeve. 13.The apparatus of claim 1 wherein the excising member-expanding structureincludes elements incorporated into the extension sleeve allowingcentrifugal force to expand the excising member upon rotation of theexcising member.
 14. The apparatus of claim 1 wherein the excisingmember-contracting structure comprises a spring associated with anelement within the extension sleeve.
 15. The apparatus of claim 2wherein the excising member-contracting structure comprises resilientspring forces within the material of the blade.
 16. The apparatus ofclaim 1 wherein the extension sleeve defines an infusion channel forinfusing fluids to a region near the excising member from the proximalend of the extension sleeve.
 17. The apparatus of claim 1 wherein theextension sleeve defines an aspiration channel for aspiration of fluidsfrom a region near the excising member to the proximal end of theextension sleeve.
 18. The apparatus of claim 17 including a filterstructure for collecting excised tissue aspirated from the region nearthe excising member.
 19. The apparatus of claim 1 including a rotatablescrew member carried by the distal end of the extension sleeve forextracting tissue.
 20. An excisional apparatus for use in excisingtissue from the interior of the body, comprising:a platform; and aneedle assembly mounted on the platform, the needle assemblyincluding:(a) a longitudinally extending extension sleeve havingproximal and distal ends and defining a longitudinal axis, said proximalend of the sleeve being coupled to a traveling arm of the stereotacticplatform, wherein said distal end carries a rotatable excising membermovable between a first position in which the excising member has atransverse sectional dimension substantially equal to the transversesectional dimension of said extension sleeve and a second position inwhich the excising member has a transverse sectional dimension greaterthan the transverse sectional dimension of said extension sleeve, theexcising member having a tip for penetrating tissue; (b) a movingstructure operatively connected to the excising member, thereby alteringthe transverse sectional dimension of the excising member between thefirst and second positions; and (c) a rotation motor operativelyconnected to the excising member.
 21. A method for excising tissue inthe interior of the body using a sleeve that carries an excising member,comprising the steps of:coupling a proximal end of the sleeve to atraveling arm of an operating platform; moving said traveling arm to alocation at an exterior of the body; piercing a distal end of the sleeveinto the interior of the body with the excising member in a firstposition; and rotating said excising member and transforming atransverse sectional dimension of said excising member from a firstsmaller dimension to a second larger dimension, thus excising tissue.22. The method of claim 21 together with the steps of:transforming thetransverse sectional dimension of said excising member from the seconddimension to the first dimension; and withdrawing the sleeve andexcising member from the interior of the body.
 23. The method of claim21 together with the step of infusing a region near the excising memberwith a fluid.
 24. The method of claim 21 together with the step ofaspirating fluid from a region near the excising member.
 25. The methodof claim 21 together with the step of extracting fluids from a regionnear the excising member by a rotating screw.